Absorption classes

Sound Absorption Class

Sound absorption classes are A, B, C, D, and E, in accordance with EN ISO 11654. Sound absorption performance is measured at frequencies between 200–5000 Hz.
Products classified as absorption class A provide the highest sound absorption performance, while products in absorption class E offer the lowest level of sound absorption.

αw
A
1,00 – 0,95 – 0,90
B
0,85 – 0,80
C
0,75 – 0,70 – 0,65 – 0,60
D
0,55 – 0,50 – 0,45 – 0,40 – 0,35 – 0,30
E
0,25 – 0,20 – 0,15
Not classified: 0.10 – 0.05 – 0.00

The recommended reverberation time is approximately 0.6–0.9 seconds at sound frequencies between 250–4,000 Hz.